Menu

Tag Archives: South America

Yesterday afternoon, officials at the Centers for Disease Control (CDC) issued an alert for travelers heading to parts of Brazil. According to the official alert, officials in Brazil’s Ministry of Health have stated that there is an ongoing Yellow Fever outbreak that started in December of 2016. Initially in the Minas Gerais state, cases are now being seen in Sao Paulo and other surrounding areas. It is estimated that over 400 individuals have been infected thus far, with 40 confirmed deaths in humans and possibly 400 deaths in certain species of native monkeys. In an effort to fight back against the spread of this disease, Brazilian authorities are launching a widespread vaccination campaign to help immunize those who are currently unprotected. The CDC recommends that those traveling to effected areas of Brazil get vaccinated against yellow fever, or receive a booster if their last vaccination was over 10 years ago. Currently, there is a shortage of yellow fever vaccine, so getting vaccinated may take longer than usual.

Map of the Brazilian state of Minas Gerais, initial site of the current yellow fever outbreak. Brazilian officials are beginning to see yellow fever cases in neighboring Sao Paulo (v-brazil.com)

Here are some facts about Yellow Fever to help keep you informed:

The Yellow Fever Virus (YFV) is an RNA virus of the genus Flavivirus – the same family of viruses that includes Dengue and Zika Virus

Yellow Fever is commonly found in South America and Africa

As with many other diseases, yellow fever virus is a vector-borne disease that is spread through the bite of an infected mosquito, either the Aedes or Haemagogus The virus can be spread to other humans if a mosquito bites an infected human and transfer virus with it while taking a blood meal.

Most individuals who become infected with yellow fever will experience no symptoms or mild symptoms. For individuals who do experience symptoms, it usually takes between 3-6 days for them to appear after being infected. Common symptoms include:

Sudden fever

Chills

Severe headache

Body aches

Nausea / vomiting

General weakness and fatigue

In some cases (15%), the disease takes a severe course and includes symptoms such as high fever, jaundice, bleeding, shock, and possibly, death.

There is no treatment for yellow fever, so hospitalized patients will receive general supportive care until the disease works its way out of the body

How to minimize your risk of contracting yellow fever:

Get vaccinated!! Unlike other diseases in its family, the yellow fever virus vaccine is very effective at inducing immunity and does not require a booster in most cases. If you live in or are traveling to a region where yellow fever has been known to transmit, getting vaccinated is one of the best ways to remain safe

Use mosquito repellent – repellents containing DEET, picaridin and oil of lemon eucalyptus have been proven to work the best

Wear appropriate clothing – long sleeve tops and long pants are most effective at minimizing the amount of exposed skin that a mosquito could bite

Avoid going outside at dusk and dawn – mosquitoes are most active during these times, so avoiding them will help minimize your risk of being bit

The Aedes mosquito, one of the species of mosquito that is involved in the transmission of yellow fever (bbc.com)

So, it’s been a while since I first wrote about Zika Virus… Today, almost every major news outlet carried the story that the Deputy Director of the CDC publicly stated that “Zika is scarier than we initially thought.” Today alone, I noticed this quote on the front pages of many news apps and papers. Given the fear that this headline easily instills in others, I figured this would be the perfect time to break down the facts of Zika, as it is currently understood.

Since my last Zika post, it has been shown that Zika Virus can be transmitted sexually, with 7 confirmed cases in the US mainland resulting from this.

Zika Virus is actively spreading throughout most of South America, all of Central America, and is beginning to spread through North America, including 30 states in the US.

Caribbean islands, especially Puerto Rico, are predicted to have a large increase in their number of Zika cases in the near future as we head into the summer months and there is increased interactions between mosquitos and humans

The CDC is warning women who are pregnant, or who are considering becoming pregnant in the near future, to avoid traveling to regions of the world where Zika Virus is actively transmitting.

Zika virus has been linked to an increase in the rates of microcephaly, particularly in Brazil, however not all pregnant women who contract Zika Virus will give birth to babies with deformities

It is possible that Zika Virus is associated with an increase rate of other birth defects, including vision problems, auditory deficits, and abnormal growth

As with many diseases, if you are infected with Zika Virus and the body fights off the infection, there is little to no risk that you will contract the virus again given your body’s immune response and memory

The White House, as recommended by the CDC, is diverting $589 million dollars in funding that was earmarked for Ebola prevention to promote research into the Zika Virus

Map showing the countries where Zika is actively transmitting, as of April 12, 2016 (CDC.gov)

There is still much to learn about Zika Virus and the research community is examining new ways to study, diagnose, and treat Zika Virus. As more developments arise, I will definitely post more updates to keep you informed! Thanks for reading my blog, and please let me know if you have any questions or comments about any of the diseases I have talked about so far. If you have suggestions for other diseases for me to talk about, please comment them below!

While the news has continued to focus on new developments in the Zika Virus, another, more-widespread virus, is utilizing mosquitos as a mode of transmission. Malaria is caused by Plasmodium parasites, and is transmitted to humans by the Anopheles mosquito. The life cycle of Plasmodium parasites occurs in both mosquitos and humans.

Plasmodium life cycle (CDC.gov)

When the parasite is brought to humans by the mosquito, the parasite infects and begins causing symptoms. In mosquitos, the parasite lives without affecting the host in a negative way. As seen in the map below, malaria is most commonly noticed in central Africa, parts of Asia, and some countries in South America. Malaria is also seen in less frequent amounts throughout central and eastern Asia, central America, and parts of Mexico. Children, pregnant women, those who have compromised immune systems, and those who have never traveled to a region with Malaria are most at risk to contract the disease.

Distribution of malaria transmission rates throughout the world (CDC.gov)

Malaria usually presents 7-30 days after being bitten by an infected mosquito. Many times, malaria is treatable if diagnosed quickly. The primary symptoms include fever, sweats, headaches, chills, and vomiting. As the disease progresses, generally in the next 48 hours after symptoms are first observed, symptoms can worsen, including seizures, kidney failure, hypoglycemia, blood coagulation, and severe fevers. If not treated quickly, malaria can become fatal.

Fortunately, there are treatments available for those who are diagnosed with malaria, and many are effective if started quickly after diagnosis. Many drugs focus on killing the parasite that causes malaria. While these treatments exist in the United States and other developed countries however, they are not as accessible in many of the regions that are hit the hardest by malaria.

One of the most common problems noticed when a new disease emerges and the scientific community races to study it is the problem of under reporting. Under reporting in disease research can be seen at the case-reporting level (when local doctors incorrectly diagnose a disease and do not alert the proper authorities) or at a larger level, where whole countries do not properly understand and report the prevalence with a disease.

Under reporting can have serious consequences in infectious disease research because when scientists need to understand the severity of a disease, they will be unable to get an accurate and true picture. In the current Zika Virus outbreak in South America, one of the major problems being seen is the lack of accurate records as to the prevalence of microcephaly in children before the Zika outbreak. Scientists want to examine if there truly are more cases of microcephaly now than before, but the lack of records is proving to make the task difficult to complete.

Another example of where under reporting is proving to be a problem is in the study of Melioidosis, also known as Whitmore’s disease. Many people have never heard of this disease, (I haven’t heard of it before writing this post!!) but it is one of the most prevalent diseases spreading through many developing nations, such as India, Brazil, and other tropical areas. Melioidosis is caused by a shape-changing bacteria in contaminated soil and water, and it can infect both humans and animals. A new study, published in Nature Microbiology, estimates that this disease is under reported in 45 countries where it is known to exist, and is present in 34 more countries that do not report it yet. This is a serious problem because Melioidosis can be fatal within 48 hours of symptoms occurring. In these developing nations, where access to healthcare is limited and people live very close to one-another, this under reported disease can cause a serious problem in the future.